Hello Here the code I try to use I get an array of (HklFactory *) via the GetAll method and I want to read for each of these HklFactory the name of the factory with the NameGet method. -- data HklFactory newtype HklFactory = HklFactory (Ptr HklFactory) deriving (Show, Storable) hklFactoryGetAll :: IO [HklFactory] hklFactoryGetAll = alloca $ \ptr -> do factories <- c_hkl_factory_get_all ptr n <- peek ptr peekArray n factories foreign import ccall unsafe "hkl.h hkl_factory_get_all" c_hkl_factory_get_all :: Ptr Int -> IO (Ptr HklFactory) hklFactoryNameGet :: Ptr HklFactory -> IO String hklFactoryNameGet factory = do name <- c_hkl_factory_name_get factory peekCString name foreign import ccall unsafe "hkl.h hkl_factory_name_get" c_hkl_factory_name_get :: Ptr HklFactory -> IO CString main :: IO () main = do initGUI factories <- hklFactoryGetAll names <- mapM hklFactoryNameGet factories print factories print names the signature of the C method are: typedef struct _HklFactory HklFactory; HKLAPI HklFactory **hkl_factory_get_all(size_t *n) HKL_ARG_NONNULL(1); HKLAPI const char *hkl_factory_name_get(const HklFactory *self) HKL_ARG_NONNULL(1); when I run the haskell code, I just get garbage when I try to extract the name of all HklFActoies here the output [HklFactory 0xb777b920,HklFactory 0xb777ba6c,HklFactory 0xb777ba98,HklFactory 0xb777bac4,HklFactory 0xb777bbf8,HklFactory 0xb777bef8,HklFactory 0xb777c4f0,HklFactory 0xb777c524,HklFactory 0xb777c6c0,HklFactory 0xb777c784,HklFactory 0xb777c8a8,HklFactory 0xb777c8dc,HklFactory 0xb777c908,HklFactory 0xb777c9cc] [",v+v<w\STX","2v,vw\EOT","2v|.vw\EOT","2v\DC40vw\EOT","5v\\3v\DC4w\EOT","_8v86v\DC4w\ACK","z@v9v\fw\ACK","@v\EOT<v@w\ACK","EvBvw\ACK","GvEvw\ENQ","yNvGvw\ACK","NvHJvw\EOT","Nv,Lv$w\ENQ","PvNvw\EOT"] Instead of human readable names I get this garbage. So I do not understand what is going on and what is wrong in my haskell code. thanks for your help Frederic